Radio frequency (“RF”) communications, such as cable TV (“CATV”) and internet services, are delivered to subscribers through lines and cables. Major cable operators have hybrid fiber coaxial (“HFC”) architecture in which a fiber optic line runs from an upstream source, such as the plant or headend, to a downstream local node. At the node, the fiber optic line is coupled to coaxial cables which eventually connect individual subscribers to RF services.
The provision of such RF services is inherently limited by the physical hardware the cable operator installs and controls. Cable operators attempt to forecast technology improvements, population growth, and telecommunication needs as they install these lines and cables. However, this task is difficult and not always accurate.
In some regions, nodes are unevenly distributed with respect to the population density. This can result in some subscribers receiving different service levels: a node serving only several dozen subscribers will generally deliver better performance to its subscribers than will a node serving a dense neighborhood of several hundred or more subscribers. Preferably, each node would serve the same number of subscribers, so that node distribution would be even and balanced. However, later node balancing by installing nodes in subscriber-dense areas is time- and labor-intensive and expensive, and most cable operators resist it.
To reduce the number of subscribers per node, some cable operators employ a technique called node splitting. Node splitting halves the subscriber density, thereby increasing the bandwidth for the node. When a node is split, one side of the split maintains its previous or original signal directionality or polarity. However, on the other side of the split, the directionality is reversed or inverted. Many CATV devices are preferably uni-directional, and this reversal can cause performance issues, especially in passive devices.
Flipping a device is sometimes one approach some operators use. However, simply physically flipping a device often is not a solution because of the dedicated footprint of the existing device; the footprints of many CATV devices are keyed and asymmetric, meaning they cannot simply be flipped or rotated. Taps, or directional couplers, are examples of such devices. Further, flipping a device is expensive, as it usually requires cuts and splices to be made. Various solutions have been proposed to address this problem. For instance, the CATV device can be completely replaced with one which accommodates the reversed direction. Alternatively, a portion of the existing device can be removed and replaced. These solutions, of course, require changing out the tap lies and may require changing the hard lines to the tap. This is expensive and breaks lines which are in known working order. An improved CATV device which accommodates and rectifies this signal polarity reversal is needed.